Risk Management and Hedging Activities (MEC) Not Designated as Hedging Contracts (Details) (MidAmerican Energy Company [Member], Not Designated as Hedging Instrument [Member], Commodity Contract [Member], USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
MidAmerican Energy Company [Member] | Not Designated as Hedging Instrument [Member] | Commodity Contract [Member]
Regulatory Assets (Liabilities), Net, Derivatives [Roll Forward]
Beginning balance	$ 10	$ 45
Changes in fair value recognized in net regulatory assets	42	(1)
Net (losses) gains reclassified to operating revenue	(19)	3
Net losses reclassified to cost of gas sold	(1)	(23)
Ending balance	$ 32	$ 24